Volvo All Engines (2010 Emissions) Fault Code: SPN 4374 FMI 1 PID: PSID 87 Aftertreatment 1 SCR Catalyst Reagent Pump Motor Speed

The aftertreatment control module (ACM) uses the aftertreatment diesel exhaust fluid (DEF) dosing pressure sensor value to adjust and maintain DEF pressure at the DEF dosing valve by controlling DEF pump speed. If the pressure decreases below expected value when the pump is in initial pressure build-up mode or if the pressure increases above expected value when pump is in idle speed mode, the ACM considers DEF pressure outside of normal operating range and indicates a malfunction in a DEF dosing pressure sensor.

Conditions for diagnostic trouble code (DTC):
1) Aftertreatment Diesel Exhaust Fluid (DEF) Pump Motor Speed Below normal

Observable symptoms
1) No aftertreatment diesel exhaust fluid (DEF) dosage

Probable cause
1) Frozen Aftertreatment Diesel Exhaust Fluid (DEF) Pump
2) Restricted Aftertreatment Diesel Exhaust Fluid (DEF) Pump
3) Aftertreatment Diesel Exhaust Fluid (DEF) Pump

Detailed information
1) Possible engine de-rate